On an overcast August afternoon in 1967, 1st Lt. David Waldrop was in the cockpit of an F-105D, call sign “Crossbow 3,” as part of a mixed force of 36 F-105s and F-4 Phantoms aiming to strike Yen Vien, the largest rail yard in North Vietnam. It was Waldrop’s 53rd combat mission in the Thunderchief, a nuclear strike aircraft unsuited for dogfighting.

As Waldrop’s flight of four 34th Tactical Fighter Squadron F-105s came off the target after dropping 750-pound M117 bombs on Yen Vien, the young lieutenant and his flight leader saw three North Vietnamese MiG-17s diving on another flight of Thunderchiefs.

“As I rolled to the right, I looked down and saw two MIG-17s. One was on the tail of an F-105 at the time,” Waldrop recalled. He yelled for the 105 to “break right!” as he dove toward the MiG. “I plugged in my afterburner, picked up a little airspeed, and closed in.”

With his throttle full-forward, Waldrop’s massive, powerful F-105 closed in on the smaller MiG at Mach 1.2 (913 mph). Ignoring his marginally useful bombing gunsight, Waldrop simply filled Crossbow 3’s windscreen with the MiG-17. Firing at close range, he saw debris fly off the MiG as he overtook it, going supersonic.

“I shot by them [the MiG and 105] so fast it’d make your head spin,” Waldrop said.

Faced with shattering MiG pieces, Waldrop pulled up hard to avoid them, flying into the overcast sky and rolling inverted. As he dropped the fighter’s nose back out of the clouds, still inverted, he saw another MiG-17 passing below, its afterburner glowing. Waldrop throttled back, rolling upright in the dive, and again filled his sights with the MiG.

“I started hosing off my cannon at him. Shortly afterwards, some fire shot out from his wingtips and about midway across the wing and he started a slow roll over to the right. I backed off and fired again. He continued rolling right on in and blew up when he hit the ground.”

The Republic F-105 Thunderchief had a hard life. A lack of reliability and in-flight systems failures plagued its early career. But it admirably took on one of the toughest air combat assignments in history—bombing targets and suppressing surface-to-air missiles in Vietnam.

Of the 833 F-105s produced, 334 were lost in combat along with over 150 aircrew. Despite its depressing 40 percent attrition rate, the F-105 was a qualified success and would become an icon. For that, we can thank those who designed and adapted it, and those who flew and fought in it. Men like Waldrop.

The 388th Fighter Wing at Korat Royal Thai Air Base in Thailand, from which Waldrop flew, gave him credit for two kills, but the Air Force later confirmed only the second. That kill had additional confirmation from famed F-4 pilot, Col. Robin Olds, who was lining up the same MiG with a Sidewinder when Waldrop blew through his shot, chasing the 17.

After debriefing and painting red stars on his 105 at Korat, Waldrop was approached by his Wing Commander, Col. John Flynn. Flynn had just gotten off the phone with Olds, calling from his own base at Ubon, Thailand.

“I want to confirm some great goddamn son of a bitch’s kill today!” Olds said to Flynn.

From Nuclear Striker to Triple Threat

The F-105 Thunderchief was designed by a team led by a Georgian emigre named Alexander Kartveli, who had previously designed Republic’s legendary P-47 Thunderbolt, F-84 Thunderjet, and F-84F Thunderstreak. The F-105 was intended to be a replacement for the F-84F and owed some of its design elements to its predecessor.

But the Thunderchief was conceived from the outset with one purpose: to be a supersonic, low-altitude penetrator capable of delivering a nuclear weapon to a target deep within the Soviet Union.

Designed with a 45-degree swept wing that deliberately cut corners on maneuverability, the 50,000-pound Thunderchief—the largest single-seat, single-engine combat aircraft ever fielded when it entered service in 1958—relied on speed for survival and an internal bomb bay to hold a nuke.

Key to its speed was its single Pratt & Whitney J75 turbojet, which produced a maximum 24,500 pounds of thrust in afterburner, not far from the latest GE F110 turbojets that provide the new F-15EX with 29,000 pounds of thrust each.

Retired Col. Vic Vizcarra, a former F-105 pilot and author of Thud Pilot: A Pilot’s Account of Early F-105 Combat in Vietnam, called the J75 a “rough tough” engine capable of taking flak damage, ingesting the 105’s own gun panels and “keeping on ticking.”

Turned out in shiny natural metal, the F-105Bs that entered the Air Force fleet in the late 1950s and early 60s stood alert at U.S. bases, ready to deploy to Europe with their nuclear bombs. They also performed in airshows. The USAF Thunderbirds demonstration team introduced F-105s as replacements for their F-100 Super Sabres in 1964.

Modified for the Thunderbirds’ aerobatics, the Thunderchiefs were awe-inspiring to watch … for six performances. A catastrophic structural failure of Thunderbird No. 2 in a landing pitch-up maneuver during a show at Hamilton Air Force Base in California killed the 105’s pilot, Capt. Eugene J. Devlin, as the Thud broke up around him just 50 feet off the ground. The Thunderbirds returned to flying the Super Sabre through 1969.

As they did so, an all-weather attack version, the F-105D, was reaching squadron service. It was the definitive version of the 105, capable of delivering a range of conventional bombs and rockets, as well defending itself with Sidewinder air-to-air missiles.

By that time, the big fighter-bomber had acquired a slate of nicknames including “Ultra Hog,” “Lead Sled,” and “Thud.” The first derived from its F-84 lineage, the second from its high speed, low-turn-rate character, and the third from its early tendency to fail in-flight.

The F-105’s advanced systems were partly to blame. The fifth aircraft in the famed Century Series, it was more of a complete “weapons system” than its predecessors, featuring the first integrated Doppler radar, inertial navigation, and fire control systems. Despite such technologies, it was also designed for a short nuclear campaign. Extended use in a lengthy conventional war exposed problems from a poor hydraulics layout to fuel tanks that were not self-sealing.

The combination of these shortcomings, with the F-105D’s conventional weapons capability, led early 1960s pilots to sarcastically refer to the Thud as a “Triple Threat”—it could bomb you, strafe you, or fall on you.

The problems were addressed via successive upgrades to the D and the later two-seat F-105F. By the time F-105s began flying and fighting in Vietnam, “Thud” became a term of respect.

War Horse, Work Horse

In the first five years of the Vietnam War, the F-105 conducted 75 percent of Air Force bombing missions over North Vietnam. They were incredibly dangerous, yet Thud pilots were expected to complete 100 of them during their combat tours.

It was a reality reflected in a 1966 documentary on the 421st TFS “Fighting Cavaliers” who flew from Korat. The movie title, There Is A Way, riffed on the Thud pilots’ standard quip that “there ain’t no way” they were making it home alive after 100 sorties.

The movie shows, with admitted corniness, who the Thud pilots were—generally older, more experienced pilots, including grandfathers from diverse flying backgrounds, even bomber pilots. With few exceptions, they loved the Thud and trusted their lives to it. As such, they remember every detail of the airplane.

Vizcarra liked the 105’s relatively spacious cockpit, with its vertical-tape instrument panel displays and detail touches like a built-in thermos bottle with a drinking tube located behind the ejection seat headrest. “When you were coming off a target with adrenaline pumping,” Vizcarra recalled, “you’d end up getting cotton-mouth, very dry. A good sip of water was just the right thing.”

The bomb bay that held the TX-43 nuclear weapon in early F-105s became the hold for an extra 390-gallon fuel tank, easing some of the short fuel-range concerns that came with the Thud. The 105’s four “flower petal” speed brakes were engine-nozzle doors that extended in pairs when the pilot needed to slow the airplane. They would also be open when taxiing to reduce thrust, keeping the aircraft’s ground speed manageable while the engine maintained sufficiently high rpm to run accessories.

Retired Thud pilot Col. Marty Case pointed out that the Thunderchief’s sleek design even lent it a measure of stealth, making it tough for even U.S. controllers to see the 105. “The [ground control approach] radars would lose the airplane. Not only was it smooth shaped, the engine is what we call ‘buried.’ The radar can’t look down the intake and see the engine … it’s buried within the fuselage.”

But for surviving bombing campaigns on bridges, railroads, and other dangerous targets in North Vietnam, nothing beat the F-105’s blistering speed.

“It was a very solid, stable airplane,” Vizcarra said. “That baby loved to go fast. The faster it went, the faster it wanted to go. Because it was so fast, it also wanted to go in a straight line.”

In a straight line, the F-105’s low-altitude speed was limited to 810 knots (930 mph) due to the tendency of its canopy-sealer to melt. But with lives at stake, they did go faster in Vietnam, up to 870 knots (1,001 mph) right on the deck, Vizacarra remembered.

Speed was life for the most dangerous Thud sorties: the surface-to-air missile (SAM) hunter-killer “Wild Weasel” missions that two-man crews in the F-105F flew near Hanoi. The two-seat trainer variant F-105F was 31 inches longer than the single-seaters to accommodate a rear cockpit. The 143 Fs built basically flew like the F-105D, but for Wild Weasel duty were modified with special radars and jamming systems. Instead of bombs, they carried Shrike missiles, which homed in on SA-2 SAM’s radar signals.

Taking out the 100 Soviet and Chinese SAM sites operating around Hanoi by 1966 was vital but costly. Eleven F-105Fs arrived at Korat in May 1966, and another seven deployed to Takhli Air Base, also in Thailand, in July. All seven of the Takhli F-105Fs were shot down within six weeks.

In their F-105Fs and later F-105Gs, the Weasels were not only first in, but also last out on a strike. However, their presence was often enough to intimidate the SAM operators and make them turn off their radars, allowing American strike packages to reach their targets and get out alive. Former Thud pilot and author, Col. Jack Broughton, called the Wild Weasel missions “the grimmest contest yet conceived between sophisticated air and ground machinery and people.”

The sentiment could be applied to most F-105 missions, explaining why so many were lost and why the Thud was pulled from service in Vietnam by 1970. What’s harder to explain, but easy to admire, is the dedication of the men that flew them. Lt. Karl Richter was one of many examples.

The soft-spoken Richter was the youngest pilot to shoot down an MiG in Vietnam at the age of 23. He completed 100 missions in the F-105D with the 421st TFS at Korat, then asked to be allowed to fly another 100 on a second tour.

Richter is seen in There Is A Way, explaining his motivation to stay in combat and quipping, “I’m too mean, they’ll never get me.” He had already won the Silver Star and the Air Force Cross for leading a flight into the teeth of North Vietnamese air defenses in April 1967.

On his 198th mission on July 28, Richter was taking a new pilot in the 388th Tactical Fighter Wing north as his wingman on a checkout mission to the relatively safe Route Pack 1 area. Spotting a bridge, he instructed his wingman to circle as he rolled in on the target. In the dive, Richter’s 105 was hit by anti-aircraft fire. He pulled up and turned toward Korat, but the Thud wouldn’t hold together. Richter ejected. His wingman had already alerted air rescue and a Sikorsky HH-3E “Jolly Green” was en route to a rough limestone ridge where his chute landed.

When the Jolly Green crew found him via his emergency beacon, he was dying. Whether his parachute had collapsed or a wind gust had thrown him into the limestone wasn’t clear, but the dedicated pilot perished.

There is no confusion about Karl Richter and his fellow airmen who flew the F-105. They were badass and so was the Thud.